X w walter weight



tetra strat fitte.

-WALTER WRIGHT, OF DANVERS CENTER, MASSACHUSETTS.

Letters Patent No; 62,797, datefZ, z.7IIa1ci-l2, 1867.

IMPROVEMENT 1N, cnr-OEE vALvE- eEAEeE lSTEAM ENGINES.

TO ALL PERSONS TO WHOM THESE PRESENTS SHALL COME:-

Beit known that I, lVALTER lrVRIGHT, of Danvers Center, in the county of Essex, and State of Massa; chusctts, have invented a new and useful or improved Variable Cut-Ofi` for Steam Engines; and I do hereby declare the saine'to be fully described in the followingl speciication, and represented in the accompanying' drawingspo'f whicl I I ligure 1 isla top view; and v Figure 2, a longitudinal section of my invention as applied t'o an engine.

This cut-oil` is designed-to :be worked by atgovernor, to be applied so as to raise and lower themain arm ofthe main shaft, to be hereinafter explained.

In the drawings, A denotes the cylinder of the engine; B, the piston; C, the connecting-rod; D, the main shaft; and a, the bell-crank of such shaft. l

The steam chest is shownl at E as provided with one eduction passagdb, and two induction passages, c d, leading from its valve-seat.- The two passages or ports, c d, go to opposite ends of the cylinder, and the eduction passage Z1 should lead to an escape pipe in the ordinary way. The steam kchest is to be capped by a cover,- and to be provided with an induction pipe, to' lead steam into such chest. The slide-valve of the chest is shown at 4:E as provided with lthree rectangular chambers, e j' u(/,arranged within'it and with respect to the ports, as

exhibited in fig. 2, an under side view of 'the valve being'shown in Figure 3, and a top view' of it in Figure 4; Each of the two extreme chambers, c and g, has three or any otherV suitable numberA of slots, z, 7L @leading upward from it to and Vthrough the top surface of the valve. On this surface, andover the two extreme chambers, eg, are placed two auxiliary valves or registers, G H, which. are ilat plates of metal, designed to slide freely on the slide-valve F in longitudinal directions. Each of these auxiliary valves has a series ofslots', iii, made through it, corresponding in' number, distance, arrangement, and size, withl those ofy the chambers c org with which the valve 4Gr or H isito act; and italso has a trapezoidal projection or stop, I, extended upward from it. The inner inclined side of this projection is formed with a series of steps, as shown at k, they being to operate with one of two arms, Z m,projecting from two stopshafts, it o, arranged transverselyin the steam chest, and con-4 nected by a tooth, @from one of them, being extended into a fork or notched projection, g,vof the other. This connection of the twoshafts should be such that, when the longer of them is revlved any distance, it shall revolve the other a like distance, but in a contrary direction. To an arm, li', projecting from `the main stopeshaft n, a'

ball-governor of Vthe engine is to be applied so as to enable it to operate such armin such manner as to turn the shaft on its axis, in either direction, in'order to raise orfdepress the arms Z m, as circumstances may require; The slide-valve is designed to be operated in the usual way, viz, by a rocker-shaft, K, provided with one crank-arm, having a pin to enter a notch in the valve-rod s. The said rocker-shaft may have a reciprocating rotary motion given to it by cranks and a connecting-rod applied to it and the main shaft. it matters not what well-known means are adopted to produce the proper and necessary movements of the valve F in order that steam from the valve chest Vmay b'e caused by such movementsto pass-alternately into the extreme parts of the cylinder, and be exhausted through the middle or exhaust port. Each' of. the auxiliary valves will be carried, alternately, back and forth by the main slide-valve, and by it will be forced against the next adjacent end of the steam chest, which will stop the motion of the auxiliary valve during or while the main slide-valve may continue in its movement. At the close of the movement of the slide-valve the openings of the `auxiliary valve will be directly over its fellow openings of the main slide-valve, so as to allowsteam to flow from the steam chest into the cylinder. The steamwill continue to so iiow until, by the next movement of the main slide-valve, the trapezoidal stop' of the auxiliary valve is carried against the next'adjacent arm Z or m, when the motion Vof the auxiliary Valve will be arrested. Theinain slide-valve, continuing its movement underneath the auxiliary'valve, the latter will at wonce close er cut off `the passage ofsteam into the cylinder. The higher the arms lm may be elevated, the longer will be the time before the auxiliary valve will cut oil' the steam, because the longer it will be before the stop of the auxiliary valve will reach its arresting arm. Thus it will bey seen that, by the action of the governor, the eut-off, when more steam may be wanted, will be longer in movement prior to cutting off the steam, and thus a greater amount of 4steam will flow into the cylinder than would be the case'were the auxiliary valve sooner arrested.

I do not claim the combination of the two registers 0'1- valves Gr H, und mechanism forope'rfting'themyby means of a governor, with the slide-valve F, madewith passages and chambers, as described; `no rdo I claim the application 0f trap'e'zoidel projections to the auxiliary valves G H, in manner and to be operated by mechanism such :ts-is described in the United Stttes Patent No. 11,055, dated June 18 1854-. What I claim as my invention or improvement has special reference to the mechanism for operating the two :tnxiliory vrltlves nppliedto the main vulve, and having trapezoidal projections I I, as described. By making each 'of the said projections with n series oi' steps in its working side, as described, they will operate tobetter advantage than :in inclined plane, as there is no such 'tendency of them to counternct 4the eiect of the governor, when the slide-valve F is in movement, as is incident to an inclined vplane. Furthermore, my mechonisim.arranged between the projections, mul for operating rvith them, has advantages in thcnpplication and Working otl the governor.

Therefore, what I claim as my invention or improvement, is its follows: v

I claim the construction of each of the trapezoi'dal projections I I, with oisets or steps, as set forth, to

operate in combinationwith the arms Zvmand the two sliafts, n o, arranged and connected in manner and to operated-s described. i

I also claim the combination :ind arrangement of the shafts 7L 0,tlie arms lm and i', when arranged in manner and to operate with the trnpezoidirl projections I I, fixed to the auxiliary vulves G H, applied lo the main slide-valve F, as described. i l

WALTER WRIGHT.

' Witnessesz' R. H. EDDY, F. PQHALE, Jn. 

